Control system



P- MCSHANE CONTROL SYSTEM Oct 1929.

Filed Sept. 19, 1927 F rward 5 a 6 l5 /6 3 I50 I51, Forward Fan/arse L 7I70 LA Forward Fever 7a Fig. 1.

INVENTOR Phelan M0 Shane,

ATTORINEY Patented Oct. 1, 1929 UNITED STATES PATENT OFFICE i PHELANICSHANE, OF PITTSBOBGH, PENNSYIlVANIA, ASSIGNOB T WESTINGHOUSE ELECTRIC& IANUIAO'1'UBING COMPANY, A CORPORATION OF PENNSYLVANIA com'nor.sYs'rEu a lication m September s, 1927. Serial No. 220,562.

My invention relates to improvements in control s stems and.particularly to control systems or a main controller actuated fromliable in operation.

remote control stations. v

The object of my invention, generally stated, is to provide a remotecontrol'system,

which will be simpleinjconstruction and re- It is also an object-ofinvention to provide for operating a" plurality of magneticdevices fromanumberpof distant control stations by means of a-single controlconductorapparent w en the description set forth here-' inafteristaken inconnectionwi'th the accompanying drawing, wherein; a

Figure 1 is a simplified schematic diagram of a control system connectedin accordance with this invention, and

Fig. 2 is a diagrammatic view of the control system shown in Figure 1adapted for controlling-the 0 ration of a reversible motor. While theinvention may be utilized for many purposes it may be illustrated toadvantage in connection with-a system for controlling the operation ofthe'motor 1 illus.- tratedin Fig.2. To simplify the following ifll'ts'illstted'th desq'np e emen' u m m e remote control switches suchas 150 is thrown schematic diagram of Fig. 1 andthose illustrated inFig. 2. which are similar are noted by the same indicating numerals; Thecontrol circuits foroperating the. various mechanisms in the two figuresbingidentical they :51 be either positive of negative depending may bemore easily tracedby consideringFi g.

1inconnection withFig.2; p The motor'l beinga series type direct-fcurrent motor, thev reversal of the same can be accomplished by simplyreversing the di-' rection of current flowing through the arma--- tureand to -accomplish this reversal, two pairs of a well knownconstruction, having actuattheir actuatin co of reversing contactors 2and 311ml 4 and 5:-

ilngefioils 2a, 3a, 4a and 5a, respectively, are uti- The motor 1 maybeconnected to any source of supply which in this case is the line conductors 6 and 7 as illustrated in Fig. 2. A switch 8 is rovided forclosing a-circuit which exten s from the line conductor 7, throughactuating coil9a of the overload relay 9, the interlock on contactor 10,and assuming the reversing contactors 2 and 4 are closed, contactor 2,armature 1aof the motor 1, contactor 4, the series field winding 13, to

the positive line conductor 6. If the motor reversing contactors 3 and 5are'closed instead of the reversing "contactors 2 and 4, the

circuitleading'through' the armature will be by way'of contactor 5,through the armature 1a ina direction opposite to that previouslytraced. through thecontactor 3, the series field winding 13 to thepositive line conductor :6, and the motor 1 will operate the oppositedirection.

tors as desired from any number of remote control stations, such as 15,16, and 17, the system illustrated in both Figs. 1 and'2 is ro- In orderto actuate the reversing contacvided. The remotecontrol stations are ilustrated by single pole switches '15a, 16a'and 17a connected to a singleconductor orcollectorv rail 18 and disposed to make contact with a pairof contact points 15b and 15a, 16b and 160, 17 band 17 a, respectively,which are connected to the positive and negative sides of the lineconductors 6 and 7 respectively. It will be seen, therefore, that whenone of the into engagement with one or the other of the e impressed uponthe single conductor 18 -uponwhether-it is connected to the positiveline conductor 6 ductor 7 v In the controller proper there is provided apair of selector contactors 21 and 22 which are double acting tivspes ofcontactors and have or the negativeline con rectly across t e source ofsupply that is the positive and negativeconductors 24 and 25,

' 21a and-22a connected di-.

respectively; To control the action of the selector contactors 21 and22, a single control conductor 19 is connected to a point20 midwaybetween the actuating coil 21a and 22a. When there is no voltageimpressed upon the 7 single control conductor 19, the two actuatingcoils 21a and 22a of the selector contactors will be energized and thecontactors closed, sin'cethey are connected in series relation acrossthe conductors 24 and 25 leading. from the source of supply. When thecontrol conductor 19becomes energized by actuating any one of theswitches 15, 16 and 17 to its closed position, a shunting circuitconnecting the point20, between coils 21a and 22a, is completed. -Itwill be readily understood that one of the coils 21aor22a will'become'deenergized, depending upon which power conductor is connectedto the single control conductor 19 upon the operation of any one of theswitches 15, 16 and 17'.

The two selector contactors 21 and 22 in turn control the operation ofthe main connetic contactor 28. When contactor 21 is I energized andheld open, a circuit is established which may be traced from conductor26, interlock 21b andthe actuating coil 29a of a magnetic contactor 29'.When contactor 22 is energized and held open, a circuit is establishedthrough conductor 27, interlock 22b "and the actuatingcoil 30a ofmagnetic contactor 30. The contactors 28, 29 and 30 together with a lowvoltagerelay 31 are provided for controlling the operation of thereversing switches 2 and 4, and 3 and 5, and the motor line contactor 10since these contactors are in circuit relation with the actuating coilsof the relays and contactors 28, 29

- and 30. The actuating coil 31a of the low voltage relay 31 may beenergized through two paths, one through the interlocks 29b and 30?) onthe magnetic contactor 29 and 30 and the coil 31a while the other whichis a holding circuit is through the interlock 31b andthe actuating coil31a. The first circuit or actuating circuit as will be seen byreferenceto Fig. 1 or 2 can be completed'only when contactors 29 and 30 areclosed simultaneously.

The motor 1 may be connected to the power source through a linecontactor 10 which may be closedfwhen the low voltage'relay 31 and themagnetic contactor 28 are closed. The

circuit to the actuating coil 10a of the linecontactor 10 being throughthe iiiterlocks 31b of the low voltage relay 31, the interlock 28?) onthe; contactor 28 and the actuating coil ,10a. T e actuating coils ofthe reversingcontactors 2 and 4, and 3 and 5 are energized whenthe twointerlocks 31b, 28b and the interlock 29c and 300 are closed.

Upon closing the knife switch23 when no voltage is impressed upon theconductor 19, the actuating coils 21a and 22a of the selector contactors21 and 22 will be energized and the contactors 21 and 22 actuated totheir upper positions, as viewed in Fig. 2 of the drawing, to bridgecontact members 216 and 22b re spectively. The closure of contactors 21and 22 upon the energizing of the actuating coils 21a and 22a closes thecircuit traced.hereinbefore through the actuating coils 29a and 30a. ofthe contactors 29 and 30.

When the two coils 29a and 30a, respectively, have been energized, thecontactors 29 and 30 are actuated to their closed position to establisha circuit which may be traced from the positive line conductor 24,through the in- ,terlocks 29b and 30b of the contactor 29 and circuitwill energize the actuating coil 31a of the low voltage relay31 andcause the same to close, thereby establishing a holding circuit whichextends from'theline conductors 24, through the low voltage relay 31,the actuating coil 31a and the overload relay 9 to the negative lineconductor 25.

When the contactors 29 and 30 ar'e clo-sed, the interlocks 29b and 30band the interlocks 29c and 300 are closed. Assuming now that one of thecontrol station switches 15, 16 or 17 has been actuated to a position toimpress either-positive or negative line voltage upon the conductor 19,then one of the actuating coils 2111 or 22a will be deenergizedaspreviously described. Therefore, one of the contractors 21 or 22 willfall open,'interrupting the circuit to one or the other of the actuatingcoils 29a or lock, 22c, and the actuating coil 28a of the contactor 28to the negative line conductor 25. This will cause contactor 28 to closeand energize coil 10a of the motor line contactor- 10 which isco'nnected'in a circuit that may be traced from the line conductor 24,low voltage relay 31, interlocks 28b and coil 10a to the negative lineconductor-25. Therefore,'when the contactor 28 closes, the motor linecontactor 10 will close.

I The contactor 30 being opened, when the coil 30a was detactor 30closes as described hereinbefore, thereby establishing an operatingcircuit forate in the opposite direction; f It will be notedthat if thevoltage to the.

'energized,and the contactor 29 remaining in the closed position, acircuit will be estab-' lished from positive line conductor 24 throughthe low voltage relay 31, contactor 28, the interlocks 29c the twoactuating coils 2a and 4a associated with the reversing contactors-2 and4, to the negative line con-I ductor 25. The circuit will actuate thereversing contactors 2 and 4. Therefore, the motor will start to operatein the direction corresponding to the current flowing through thesetwo-contactors.

Assuming now that it is desired to reverse the operation of the motor,then one of the master switches 15, 16 or 17 will be thrown to changethe polarity of the voltage impressed upon the line conductorl9. In thisinstance, the actuating coil 21a of contactor 21 becomes shortcircuited, and full line voltage is impressed upon coil 22a of contactor22. Upon the closure of contactor 22, the conthe reversing contactors 3and 5. This circuit may be traced from' line conductor 24, through relay31, contactor 28, interlocks30a of contactor 30, conductor 32, andthence through'a parallel circuit comprising coils 3a and a, to the lineconductor 25.

- The closure of the reversing contactors 3 and 5 thereby establishes acircuit extended through thearmature of the motor 11in adirectionopposit-e to that when the other tw'o reversing contactors wereclosed. This will cause the motor 1 to reverse and oper- System shouldfail or fall below a predetermined amount, that the low voltage relay 31will fall open, and the same can not be again closed until the circuitpreviously traced "through the interlocks 29b and b is established,which occurs only when all the master the machinery to avoid accidents.

' While I have illustrated and describeda particular embodiment of theinvention, it is intended that all matter contained herein voltagepreciate switches are their ofi positions. Thereby a lowflvoltageprotection is provided to prevent the apparatus to which the controlleris attached from starting up, after voltageis again restored to theline, unless the control switches themselves are first re turned totheir neutral position. This low (protection can be very readily ap-.

'where a system incorporating the invention is applied to steel milloperation in which it "is necessary-at all times to exercise thegreatest of care in the operation of shall be-interpreted asillustrative and not in a limiting sense, since manifestly the same maybe considerably varied without depart ing from thev spirit oi theinvention as set I claim as my invention:

ation of the motor, and a low-voltage relay disposed to render said maincontroller inoperativeinresponse to a redetermined volta e reduction,said relay Being dependent for its closure upon said governing means.

v 2; In a control system. in combination, a

main controller, a plurality of control sta tions for operating thecontroller, a single control conductor for connecting the controlstations to the controller, said main controller being provided with aplurality of selecting switches for governing the, operation of thecontroller, said selecting switches being responsive to the energizationof the control conductor, and i3, low-voltage relay disposed to renderthemain controller inoperative in response to a predetermined reductionin voltage, said low-voltage relay being dependent'for its closure uponsaid selecting switches.

3. In a motor-control system, combination, a motor, a ource of power forthemotor, means for establishing a motor circuit, a pluralityofyreversing switches disposed to be operated in pairs, relays forcontrolling the energization of each pair of reversing switches, saidrelays being disposed to effect the operation oi the reversing switcheswhen deenergized, manually oper-- able means for controlling theenergization of the relays, a low-voltage relay for interrelay beingdependent forits closure on sald relays.-

. 4, In a motor-control system, in combination, a motor, a source ofpower 'for the motor, means for establishing a motor circuit, reversingswitches-for controlling the direction ofoperation of the motor, meansfor selectively operatin the reversing switches, a manually opera leswitch for convrupting the motor circuit, said low-voltage trolling theoperation of the means for 'selectively operating the reversingswitches, a no-voltage relay for interru ting the motor circuit upon thefailure 0 voltage,-said reversing switches beingresponsive to theopening ofv the no-voltage relay, said 'novoltage relay being dependentfor its closure upon the means for selectively operating 1 the reversingswitches, whereby, when the relay is opened,,upon the failure of vol e,

it cannotbe rec osed until themanu y operable switch is operated.

: tor, means 5. In a motor-control system, in combination, a motor asource of power for the mofor controlling the suplply of power to themotor, reversing switc es for controlling the direction of operation ofthe motor, means for selectively operating the reversing switches tooperate the motor in a redetermined direction, a no-volta e relay orgoverning the means for control ing' the supply of power to the motorupon the failure of voltage, said relay controlling the operation of thereversing switches through I said selective means, said selective meansbeing disposed for operation to efiect the setting of the relay in theclosed position.

I 6. In a motor-control system, in combination, a motor, a source ofpower for the motor, reversing switches for controlling the direction ofoperation of the motor, a switch for controlling thesupply of current tothe reversing switches, means cooperative with said control switch for;selecting and operating predeterminedreversing switches, andalow-voltage relay responsive to the voltage across'the source of supplydisposed to control said switch,'said low-voltage relay being dependent,when it hasopened, on the selecting means for its closure. 5

' 7 In a motor-control system, in combination, a motor, asource-of-power for the motor, reversing switches .for controlling thedirection of operation of-the motor, a switch for controlling thesu'pply'of current to the reversing switches, means cooperative withsaid control switch for selecting and'operating predetermined reversingswitches, a low-voltage relay responsive't'o the voltage across thesource of supply disposed to control said switch, said low-voltage relaybeing dependent, when it has opened, on the selecting means for itsclosure and manual means for initiatingthe operationof the selectingmeans v 8. In a motor-control system, in combination, .a motor, a sourceof power for the motor, reversing switches for controlling the directionof operation of themotor, a switch for controlling the supply of currentto the reversing swltches, means cooperative with a said control switchfor selecting and operating predetermined reversing switches, alowvoltage relay responsive to the voltage across the source ofgsupplydisposed to control said switch, said low-voltage rela being dependent,when it has opened, on t e selecting means for its closure, a pluralityofmanual control stations for controlling the operation n of theselecting means, and a single control 7 conductor disposed to connectsaid manualcontrol stations to the selecting means. In testimonywhereof, I have hereunto subscribed my name the 12th day of September,1927. PHEL N MG HANE.

